#pragma once // // FILE: MultiMap.h // AUTHOR: Rob Tillaart // VERSION: 0.1.4 // DATE: 2011-01-26 // PURPOSE: Arduino library for fast non-linear mapping or interpolation of values // URL: https://github.com/RobTillaart/MultiMap // URL: http://playground.arduino.cc/Main/MultiMap // // HISTORY: // 0.0.1 2011-01-26 initial version (see forum) // ..... // 0.1.0 2015-03-29 // 0.1.1 2020-04-09 // 0.1.2 2020-06-19 fix library.json // 0.1.3 2021-01-02 add arduino-CI // 0.1.4 2021-05-27 fix arduino-lint #define MULTIMAP_LIB_VERSION (F("0.1.4")) #include "Arduino.h" // note: the in array should have increasing values template T multiMap(T val, T* _in, T* _out, uint8_t size) { // take care the value is within range // val = constrain(val, _in[0], _in[size-1]); if (val <= _in[0]) return _out[0]; if (val >= _in[size-1]) return _out[size-1]; // search right interval uint8_t pos = 1; // _in[0] allready tested while(val > _in[pos]) pos++; // this will handle all exact "points" in the _in array if (val == _in[pos]) return _out[pos]; // interpolate in the right segment for the rest return (val - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1]; } /* * speed optimized version if inputs do not change often e.g. 2 2 2 2 2 3 3 3 3 5 5 5 5 5 5 8 8 8 8 5 5 5 5 5 * // note: the in array should have increasing values template T multiMap(T val, T* _in, T* _out, uint8_t size) { static T lastvalue = -1; static T cache = -1; if (val == lastvalue) { return cache; } lastvalue = val; // take care the value is within range // val = constrain(val, _in[0], _in[size-1]); if (val <= _in[0]) { cache = _out[0]; } else if (val >= _in[size-1]) { cache = _out[size-1]; } else { // search right interval; index 0 _in[0] already tested uint8_t pos = 1; while(val > _in[pos]) pos++; // this will handle all exact "points" in the _in array if (val == _in[pos]) { cache = _out[pos]; } else { // interpolate in the right segment for the rest cache = (val - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1]; } } return cache; } */ // -- END OF FILE --